With the social progress and technical development, electronic products such as TV are gradually thinned in recent years. People are increasingly demanding high performance of these electronic products, so the supporting electronic parts are required to be smaller in size and thickness and improved in performance and consistency.
The woofer is an important electronic component which is widely used in the above electronic products, in the thin-type electronic devices such as liquid crystal televisions, laptop computers and the like. It is required to reduce the thickness thereof on the basis of ensuring loudspeaker performance to meet the need for thin-type electronic devices.
The woofer with traditional structure normally uses a tapered paper cone vibrating diaphragm. The tapered vibrating diaphragm comprises a voice coil in the central position thereof, and the size of the magnetic circuit system is relatively large and thick. The woofer with this structure is too thick to meet the requirement of gradually-thinned electronic products at present, and is weak on practicability.
Besides, the woofer usually has a larger caliber (i.e. larger area of vibrating diaphragm) to ensure the low-frequency sound effect thereof. If the structure in which a tabulate vibrating diaphragm combined with a voice coil (the voice coil is required to be positioned near the edge) is adopted, the vibrating diaphragm with larger area requires the voice coil to be large in size, causing difficult winding and easy deformation. Further, the magnet of the existing woofer is large in size, and the thicknesses of washers and frames are required to be smaller during thinned application, so the magnetic circuit system is easy to be saturated, and the magnet performance is excessive, leading to wastage and relatively high cost.
Based on the above factors, there is a need to improve the woofer with traditional structures to avoid the aforementioned defects.